Alert archive / South Dakota / Severe Thunderstorm Warnings in 2002

Severe Thunderstorm Warning 101, NWS Aberdeen, SD

July 21, 2002Roberts County, South Dakota

NWS Aberdeen, SD issued this severe thunderstorm warning at Jul 21, 2002, 5:11 AM CDT for Roberts County, South Dakota. It was in force for 49 min. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Jul 21, 2002, 5:11 AM CDT (10:11 UTC)
Expired: Jul 21, 2002, 6:00 AM CDT
In force: 49 min
Issued by: NWS Aberdeen, SD
Area: Counties, with a storm outline in the text

County Roberts County, SD

What was reported inside it

Time	Report	Where	Remark
Jul 21, 5:17 AM CDT	Thunderstorm Wind 60 M	Sisseton, SD

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this severe thunderstorm warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The nearest sounding before it

Aberdeen, SD (KABR), launched 00:00Z, 10.2 hours before the alert went out and 135 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 2314 J/kg
Mixed-layer CIN: -111 J/kg
Mixed-layer LCL: 2061 m above ground
0-6 km bulk shear: 39 kt
0-1 km storm-relative helicity: 38 m²/s²
0-3 km storm-relative helicity: 138 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 2.7

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

309 
WUUS53 KABR 211011
SVRABR
SDC109-211100-
/NEW.KABR.SV.W.0170.211010-211100/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE ABERDEEN SD
510 AM CDT SUN JUL 21 2002

THE NATIONAL WEATHER SERVICE IN ABERDEEN HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  ROBERTS COUNTY IN NORTHEAST SOUTH DAKOTA

* UNTIL 600 AM CDT

* AT 510 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  LINE OF SEVERE THUNDERSTORMS FROM 8 MILES NORTHWEST OF CLAIRE CITY
  TO 6 MILES SOUTHWEST OF WILMOT...OR FROM 9 MILES SOUTH OF
  LIDGERWOOD TO 17 MILES NORTHWEST OF MILBANK...MOVING NORTHEAST     
  AT 35 MPH. STRONG WINDS WILL BE THE MAIN THREAT WITH THESE STORMS.

* SEVERE THUNDERSTORMS WILL BE NEAR...
  PEEVER...CLAIRE CITY AROUND 515 AM CDT
  WILMOT AROUND 520 AM CDT
  NEW EFFINGTON AROUND 535 AM CDT

THIS STORM HAS A HISTORY OF PRODUCING DAMAGING WIND. GO INSIDE A
STURDY BUILDING AND STAY AWAY FROM WINDOWS.

REPORT SEVERE WEATHER TO THE NEAREST LAW ENFORCEMENT AGENCY. THEY
WILL RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE OFFICE IN
ABERDEEN.

LAT...LON 4536 9682 4594 9688 4594 9720 4532 9716

PARKIN

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Aberdeen, SD wrote its last area forecast discussion before this severe thunderstorm warning went out at Jul 21, 2:25 AM CDT, 2 hours 46 minutes earlier.

Area forecast discussion, Jul 21, 2:25 AM CDT, 2 hours 46 minutes before

AREA FORECAST DISCUSSION FOR CENTRAL/N-EAST SD AND W-CENTRAL MN
NATIONAL WEATHER SERVICE ABERDEEN SD
225 AM CDT SUN JUL 21 2002

MAIN ISSUE FIRST PERIOD IS PCPN THEN FOR THE REST OF THE SHORT RANGE
MUCH MORE TRANQUIL.  MCS OVER CENTRAL SOUTH DAKOTA SHOULD CONTINUE
TO MOVE/DEVELOP TOWARD THE EAST/NE AROUND PERIPHERY OF CAPPING
RIDGE.  LOOKS LIKE GOOD PORTION OF THE CWA WILL GET MUCH NEEDED
RAIN...SOME LOCALLY HEAVY BUT THIS SHOULDNT CREATE MUCH OF AN
ISSUE.  TEMPS WERE THE NEXT PROBLEM FOR TODAY.  DEBRIS CLOUDS COULD
HOLD BACK READINGS SOME...THAT AND STILL RELATIVELY HIGH DEWPOINTS.
STUCK FAIRLY CLOSE TO GOING FORECAST GIVEN DISTINCT POSSIBILITY OF
AFTERNOON SUN...PLUS PROGGED 8H TEMPS ARE SUPPORTIVE.

FOR TNT AM AIMING FOR NO PCPN AS BOUNDARY SLIDES FURTHER SOUTHEAST
AND DRIER AIR ADVECTS INTO THE REGION BEHIND SECONDARY COOL PUSH.
OVERNIGHT TEMPS TO BE SOMEWHAT COOLER THAN HAS BEEN EXPERIENCED OF
LATE.  MILDER TEMPS AND LOWER DEWPOINTS CONTINUE INTO MONDAY.

FOR MONDAY NIGHT AND EARLY TUESDAY SFC FLOW BECOMES EASTERLY UPSLOPE
ACROSS SW CWA.  PLUS FAVORABLE JET QUADRANT WILL BE OVERHEAD.
MODELS TRYING TO CRANK OUT SOME LIGHT PCPN.  HOWEVER MOISTURE STILL
SORTA SCANT AND MID LEVEL LIFT PROGGED TO BE ONLY MINOR.  THEREFORE
WILL MAINTAIN DRY FORECAST BUT LATER SHIFTS WILL HAVE TO MONITOR THE
SITUATION.  FOR NOW HAVE NOT MODIFIED THE EXTENDED.  TRICKY
NORTHWEST FLOW ALWAYS PLAY HAVOC ACROSS THIS CWA AND UPCOMING
EXTENDED LIKELY TO BE NO DIFFERENT.

.ABR...NONE.
TDK

In the hours before

Local storm report, Jul 21, 1:50 AM CDT, 3 hours 21 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ABERDEEN, SD
150 AM CDT SUN JUL 21 2002

TIME(CDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0125 AM    PIERRE                    SD   59 MPH WIND GUST
07/21/02   HUGHES

PARKIN

The office that day

Everything else NWS Aberdeen, SD issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 21, 12:49 AM CDT	Severe Thunderstorm Warning	ABR	Stanley	26 min
Jul 21, 1:14 AM CDT	Severe Thunderstorm Warning	ABR	Hughes, Sully	46 min
Jul 21, 3:24 AM CDT	Severe Thunderstorm Warning	ABR	Brown, Edmunds, Spink	66 min
Jul 21, 3:43 AM CDT	Severe Thunderstorm Warning	ABR	Clark, Codington, Day, Deuel, Grant, Hamlin	62 min
Jul 21, 4:30 AM CDT	Severe Thunderstorm Warning	ABR	Marshall	45 min

Nearby

Severe Thunderstorm Warnings in South Dakota, 2002 Every severe thunderstorm warning in 2002

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.